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Rate-responsive pacing regulated by cardiac haemodynamics.
Gianni Gasparini1, Antonio Curnis, Michele Gulizia
1Unità Operativa di Cardiologia, Ospedale Umberto I, via Circonvallazione, 50, 30174 Mestre, Venezia, Italy. g_gasparini2000@yahoo.it
Summary
Trans-valvular impedance (TVI) reliably tracks cardiac hemodynamics. This study shows TVI can effectively regulate pacemaker rate based on heart
Area of Science:
- Cardiovascular Physiology
- Biomedical Engineering
- Implantable Electronic Devices
Background:
- Trans-valvular impedance (TVI) is a proposed method for assessing cardiac hemodynamics.
- TVI is assumed to have an inverse relationship with ventricular volume.
- The potential of TVI to regulate pacemaker function requires investigation.
Purpose of the Study:
- To evaluate if TVI sensors can drive rate-responsive cardiac pacing.
- To assess TVI's response to changes in cardiac inotropic regulation.
Main Methods:
- An external DDD-R pacemaker with a TVI system was tested in 30 patients.
- Pacing rate was regulated based on stroke volume and end-diastolic volume inferred from TVI.
- Beta-adrenergic stimulation (isoprenaline) was administered to assess inotropic response.
Main Results:
- Patients showed a positive chronotropic response to isoprenaline, with increased end-diastolic and end-systolic TVI.
- The TVI inotropic index correlated linearly with the sinus rate (r(2)>0.7 in 25/28 patients).
- The TVI-indicated pacing rate closely matched the intrinsic sinus rate.
Conclusions:
- TVI provides reliable hemodynamic information.
- TVI is suitable for regulating rate-responsive pacing.
- This technology supports advanced cardiac pacing strategies.